94GHz millimeter wave radar

Abstract

The invention provides a 94GHz millimeter wave radar, and relates to the technical field of intelligent sensing. Comprising a transmitting and receiving antenna module, a radio frequency front end module and a baseband signal processing module which are connected in sequence, the transmitting and receiving antenna module is used for constructing a radio frequency link with a target and transmitting a millimeter wave signal and receiving an echo signal in the radio frequency link, and the radio frequency front-end module is used for performing signal conversion on a chirp source signal to form the millimeter wave signal and performing amplification and noise reduction processing on the echo signal to obtain a low-frequency signal; and the baseband signal processing module is used for processing the low-frequency signal to obtain an execution signal. According to the invention, the problems of insufficient resolution and bandwidth and too high design cost of the vehicle millimeter wave radar in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the field of intelligent sensing technology, and in particular to a 94 GHz millimeter wave radar. Background Art

[0002] With the development of traffic sensing technology, especially the cost of high-precision sensors such as millimeter-wave radar and lidar has gradually decreased, and its scope of application has gradually expanded to the transportation field. In particular, the application of millimeter-wave radar has been gradually promoted in recent years. It has high detection accuracy, long coverage distance, raw data carrying target speed information, and is not affected by weather, which has significant advantages. However, in the global millimeter-wave radar market, the dominant countries are Germany, the United States, Japan and other countries. Millimeter-wave core chips are monopolized by international semiconductor companies such as TI, Infineon, NXP, ADI, ST, Fujitsu, ON Semiconductor, and Renesas. In order to break the monopoly in the transportation industry, it is currently stipulated that the 76-79GHz frequency band "cannot be used for other radars set up on the ground." Therefore, the existing automotive radar can no longer be used for road traffic perception. The existing traffic radar and automotive millimeter-wave radar frequency band overlap, and there is a lack of 92-95Ghz road frequency band millimeter-wave radar equipment; the existing automotive millimeter-wave radar resolution and bandwidth are insufficient and the design cost is too high.

[0003] At present, relevant departments have decided to start the study of the frequency use planning of the 92-95GHz frequency band, intending to solve the frequency band use requirements of roadside radars in the field of intelligent transportation within the above frequency band. However, the key components do not meet the size requirements, resulting in the inability of existing hardware processes to directly produce 94Ghz millimeter-wave radars. At present, there are no 92-95GHz road millimeter-wave radar products at home and abroad, and there is a lack of millimeter-wave radar chips in this frequency band. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a 94GHz millimeter-wave radar. The present invention solves the problems in the prior art that the frequency bands of traffic radar and automotive millimeter-wave radar overlap, there is a lack of 92-95Ghz road frequency band millimeter-wave radar equipment, and the existing automotive millimeter-wave radar has insufficient resolution and bandwidth and too high design cost.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A 94 GHz millimeter wave radar, comprising:

[0007] The transmitting and receiving antenna modules, the RF front-end module and the baseband signal processing module are connected in sequence;

[0008] The transmitting and receiving antenna module is used to build a radio frequency link with the target and transmit millimeter wave signals and receive echo signals within the radio frequency link. The radio frequency front-end module is used to convert the chirp source signal into a millimeter wave signal and amplify and reduce the noise of the echo signal to obtain a low-frequency signal. The baseband signal processing module is used to process the low-frequency signal to obtain an execution signal.

[0009] Preferably, the transmitting and receiving antenna module comprises:

[0010] A first six-way power divider, a second six-way power divider connected in parallel, and a two-way power divider connected in series;

[0011] The first six-way power divider and the second six-way power divider are connected to the six-way transmitting antennas and the six-way receiving antennas respectively;

[0012] The first six-way power divider is used to distribute the millimeter wave signal so as to transmit the millimeter wave signal using six transmitting antennas, the second six-way power divider is used to collect the echo sub-signals of the six receiving antennas to obtain the echo signal, and the two-way power divider is used to collect or distribute one of the echo signal or the millimeter wave signal.

[0013] Preferably, the radio frequency front-end module comprises:

[0014] Interconnected voltage-controlled oscillator and radio frequency chip;

[0015] The voltage-controlled oscillator is used to obtain a voltage signal and convert the voltage signal into a chirp source signal to transmit to the RF chip. The RF chip is used to amplify, filter and convert the chirp source signal to obtain a millimeter wave signal, transmit and amplify the echo signal, and perform noise reduction processing to obtain a low-frequency signal.

[0016] Preferably, the radio frequency chip comprises:

[0017] frequency multipliers, power amplifiers, mixers, and low noise amplifiers;

[0018] The power amplifier is connected to the frequency multiplier, and the mixer is connected to the frequency multiplier and the low noise amplifier respectively.

[0019] The frequency multiplier is used to multiply the 91Mhz signal into a 94GHz signal, and the power amplifier is used to

[0020] The present invention discloses the following technical effects:

[0021] The present invention provides a 94GHz millimeter wave radar, including: a transmitting and receiving antenna module, a radio frequency front-end module and a baseband signal processing module connected in sequence; the transmitting and receiving antenna module is used to build a radio frequency link with the target and transmit millimeter wave signals and receive echo signals in the radio frequency link, the radio frequency front-end module is used to convert the chirp source signal into a millimeter wave signal and amplify and reduce the noise of the echo signal to obtain a low-frequency signal, and the baseband signal processing module is used to process the low-frequency signal to obtain an execution signal. The present invention utilizes 94GHz millimeter wave signals, and the system has a higher resolution and can detect finer target features. It is suitable for occasions with high precision requirements, and the 94G frequency band resources are sufficient; at the same time, after the bandwidth is large, the measurement accuracy will also be improved at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 A schematic diagram of the structure of a 94 GHz millimeter wave radar provided in an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of the FPGA clock domain workflow provided by an embodiment of the present invention;

[0025] Figure 3 A schematic diagram of the AD9910 clock working process provided by an embodiment of the present invention;

[0026] Figure 4 A schematic diagram of a radio frequency front-end module provided in an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of a radar transceiver structure provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1 As shown, the present invention provides a 94 GHz millimeter wave radar, comprising:

[0031] The transmitting and receiving antenna modules, the RF front-end module and the baseband signal processing module are connected in sequence;

[0032] The transmitting and receiving antenna module is used to build a radio frequency link with the target and transmit millimeter wave signals and receive echo signals within the radio frequency link. The radio frequency front-end module is used to convert the chirp source signal into a millimeter wave signal and amplify and reduce the noise of the echo signal to obtain a low-frequency signal. The baseband signal processing module is used to process the low-frequency signal to obtain an execution signal, decompose the execution signal to obtain a number of independent sub-signals corresponding to different detection targets. Figure 1 The 94Ghz RF module 2 transmission channel includes a front-end receiver.

[0033] Specifically, the RF front-end module is connected to the output end of the transmitting and receiving antenna modules and the input end of the baseband signal processing module, and is used to multiply the chirp source signal, amplify it, convert it into a high-frequency signal for transmission, and amplify, reduce the noise, convert the echo signal into a low-frequency signal and transmit it to the baseband signal processing module.

[0034] Furthermore, the transmitting and receiving antenna module includes:

[0035] A first six-way power divider, a second six-way power divider connected in parallel, and a two-way power divider connected in series;

[0036] The first six-way power divider and the second six-way power divider are connected to the six-way transmitting antennas and the six-way receiving antennas respectively;

[0037] The first six-way power divider is used to distribute the millimeter wave signal so as to transmit the millimeter wave signal using six transmitting antennas, the second six-way power divider is used to collect the echo sub-signals of the six receiving antennas to obtain the echo signal, and the two-way power divider is used to collect or distribute one of the echo signal or the millimeter wave signal.

[0038] Specifically, two six-way power splitters are connected in parallel and one two-way power splitter is connected in series. The two six-way power splitters are connected to six transmitting antennas and six receiving antennas respectively to form six-transmit and six-receive MIMO. Multi-transmit multi-receive MIMO uses beamforming and angle control to achieve software beamforming by changing the six phases δφ, amplifying the energy in a single direction, increasing the power and improving the directivity. Figure 4and Figure 5 shown.

[0039] Furthermore, the RF front-end module includes:

[0040] Interconnected voltage-controlled oscillator and radio frequency chip;

[0041] The voltage-controlled oscillator is used to obtain a voltage signal and convert the voltage signal into a chirp source signal to transmit to the RF chip. The RF chip is used to amplify, filter and convert the chirp source signal to obtain a millimeter wave signal, transmit and amplify the echo signal, and perform noise reduction processing to obtain a low-frequency signal.

[0042] Furthermore, the radio frequency chip includes:

[0043] frequency multipliers, power amplifiers, mixers, and low noise amplifiers;

[0044] The power amplifier is connected to the frequency multiplier, and the mixer is connected to the frequency multiplier and the low noise amplifier respectively.

[0045] The frequency multiplier is used to multiply the 91Mhz signal into a 94GHz signal;

[0046] More specifically, the frequency multiplier: multiplies the chirp signal in the low frequency band and moves it to the required high frequency band; the power amplifier: amplifies the signal to a sufficient distance to propagate in free space; the low noise amplifier: amplifies the echo signal without introducing too much noise for subsequent processing; the mixer: mixes the echo signal with the intrinsic signal to decompose the baseband signal.

[0047] Specifically, the voltage-controlled oscillator converts the voltage signal into an oscillation signal, which enters the RF chip as a chirp source with a frequency of 24 GHz;

[0048] The RF chip includes a frequency multiplier, a power amplifier, a mixer and a low-noise amplifier, wherein the frequency multiplier multiplies the 91Mhz signal into a 94GHz signal, the power amplifier is connected to the frequency multiplier and the transmitting antenna, the mixer is connected to the frequency multiplier and the low-noise amplifier, and the low-noise amplifier is connected to the mixer and the receiving antenna. Finally, the mixed signal is transmitted to the digital-to-analog converter ADC through the RF chip, and the circuit analog signal is converted into a digital signal and sent to the baseband signal processing module.

[0049] The RF chip has a center frequency of 94GHz, a bandwidth of 500MHz, a distance resolution of 0.3m, a scanning frequency of 10Hz, a scanning mode of triangular wave, a rise of 50μs, a fall of 50μs, a scanning period of 100μs, a frame of 100 triangular waves, a total of 10ms, an ADC IQ sampling rate of 31.25Msps, and a maximum detection distance of 300m. The array unit uses 6 CZ630207 chips cascaded, with a transmission power of 13dBm, a transmitting antenna gain of 15dBi, and a minimum receiving power of -119dBm.

[0050] Furthermore, the baseband signal processing platform selects XILINX FPGA processor as the radar baseband processor SoC, connects AD conversion and digital filtering in series, connects to Ethernet transceiver, and connects to the host computer through UDP packets.

[0051] Specifically, the FPGA clock domain uses a 125MHz crystal oscillator to obtain a 750Mhz signal by 6 times the frequency and inputs it into the DDR2 cache, obtains a 250MHz signal by 2 times the frequency and transmits it to the Ethernet transceiver module, obtains a 62.5MHz signal by 4 times the frequency and transmits it to the system master clock, and obtains a 31.25MHz signal by 2 times the frequency and transmits it to the ADC clock. Figure 2 shown.

[0052] Specifically, the AD9910 clock is multiplied by 29 through a 25MHz crystal oscillator to obtain a 725MHz signal, which is then passed to the system master clock, and then multiplied by 4 to obtain a 181.25MHz signal which is passed to the DAC clock. Figure 3 shown.

[0053] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0054] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A 94GHz millimeter wave radar, characterized in that: include: The transmitting and receiving antenna modules, the RF front-end module and the baseband signal processing module are connected in sequence; The transmitting and receiving antenna module is used to build a radio frequency link with the target and transmit millimeter wave signals and receive echo signals within the radio frequency link. The radio frequency front-end module is used to convert the chirp source signal into a millimeter wave signal and amplify and reduce the noise of the echo signal to obtain a low-frequency signal. The baseband signal processing module is used to process the low-frequency signal to obtain an execution signal.

2. The 94 GHz millimeter wave radar according to claim 1, characterized in that: The transmitting and receiving antenna module comprises: A first six-way power divider, a second six-way power divider connected in parallel, and a two-way power divider connected in series; The first six-way power divider and the second six-way power divider are connected to the six-way transmitting antennas and the six-way receiving antennas respectively; The first six-way power divider is used to distribute the millimeter wave signal so as to transmit the millimeter wave signal using six transmitting antennas, the second six-way power divider is used to collect the echo sub-signals of the six receiving antennas to obtain the echo signal, and the two-way power divider is used to collect or distribute one of the echo signal or the millimeter wave signal.

3. The 94 GHz millimeter wave radar according to claim 1, characterized in that: The radio frequency front-end module comprises: Interconnected voltage-controlled oscillator and radio frequency chip; The voltage-controlled oscillator is used to obtain a voltage signal and convert the voltage signal into a chirp source signal to transmit to the RF chip. The RF chip is used to amplify, filter and convert the chirp source signal to obtain a millimeter wave signal, transmit and amplify the echo signal, and perform noise reduction processing to obtain a low-frequency signal.

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